package collection;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;

public class ListDemo {
    public static void main(String[] args) {
        List<String>list = new ArrayList<>();
        list.add("one");
        list.add("two");
        list.add("three");
        list.add("four");
        list.add("five");
        System.out.println(list);

        //E get(int index):获取指定下标所对应的元素
        String e = list.get(2);
        System.out.println(e);

        for (int i = 0; i < list.size(); i++) {
            System.out.println(list.get(i));
        }

        Iterator<String>it = list.iterator();
        while (it.hasNext()){
            System.out.println(it.next());
        }
        for (String str:list) {
            System.out.println(str);
        }

        //E set(int index, E e):将给定元素设置到指定位置,返回被替换的元素---一般不接收
        //list.set(2,"six");//将list中下标为2的元素设置为six---常规用法
        String old = list.set(2,"six");//将list中下标为2的元素设置为six,同时将原数据返回old
        System.out.println(list);
        System.out.println(old);

        //重载了remove
        //E remove(int index):删除指定位置元素,并返回指定位置元素
        //list.remove(2);
        String old1 = list.remove(2);//删除下标为2的元素,并将被删除元素返回给s
        System.out.println(list);
        System.out.println(old1);
        //重载了add
        //void add(int index,E e):将给定元素e添加到index所指定的位置,相当于插入操作
        list.add(2,"seven");
        System.out.println(list);



    }
}
